In recent years, as images can be created simply and inexpensively by gravure printing, ink jet recording has come to be applied to various printing fields including special printing such as photographing, various printing, marking, and color filtering. Especially, in ink jet recording, the followings are combined, by which it is possible to obtain an image comparable to silver halide photography. Namely, it is a combination between recording heads based on an ink jet recording method for jetting and controlling fine particles, inks improved in a color regeneration area, durability, and jettability, and a dedicated paper sheet extremely improved in ink absorbance, coloring material colorability, and surface luster.
On the other hand, however, it is known that pigment contained even in an improved ink as described above gets deposited with time elapsed. It is difficult to obtain an image with a predetermined concentration if pigment is deposited. Therefore ink jet printers capable of diffusing pigment, the pigment having once deposited, again in the ink have been developed.
For example, an ink jet printer disclosed in Patent Document 1 described below includes a recording head for jetting ink onto a recording medium, a carriage that has a recording head and reciprocally moves in the main scanning direction, and an ink tank for storing ink to be supplied to the recording head, the ink tank being mounted on the carriage. The ink tank houses a spherical mover that reciprocally moves in the ink tank accompanying reciprocal movement of the carriage to diffuse deposited pigment.
[Patent Document 1] TOKKAIHEI No. 09-309212
However, although such an ink jet printer can diffuse pigment deposited in an ink tank into ink, it cannot diffuse, into ink, pigment deposited inside a recording head or in an ink supply path such as inside a communicating conduit that communicates the recording head and the ink tank.
Particularly, a pigment with a comparatively large specific gravity, such as titanium oxide contained in white ink, tends to more easily get deposited in an ink supply path due to the specific gravity thereof than a pigment with a small specific gravity for a color ink, and it is difficult to remove the pigment with a comparatively large specific gravity to outside the ink supply path. The pigment deposited in the ink supply path causes ink jetting failure, which causes a problem of lowering image quality.